Medical practice variations: what the literature tells us (or does not) about what are warranted and unwarranted variations

This paper examines the sources of practice variations and definitions of unwarranted variation, as derived from the literature. The literature suggests variables/factors related to patient health needs, doctor 'practice style' and environmental constraints/opportunities as sources of practice variations. However, this list is likely to be incomplete because of significant unexplained variation in each study. Furthermore, it is unclear which …